Circular knitting machine



Sept. 1, 1945. T. c. BROMLEY ETAL 2,385,056

CIRQCULR KNITTING MACHINE Filed sept. 28l '1942 2 sheetssheefl c; F 1/ .M l /62 ibmmwfmw,

sept. 1s, 1545.

T. BROMLEY` El AL CIBCLAR KNITTING MACHINE Filed sept. 2a,` 1942 2 Sheets-Sheet 2 FVG/4.

. Patented Sept. 18, 1945 UNITED STATES PATENT OFFICE CIRCULAR KNITTING MACHINE COmpa'ny Application September 28, 1942, Serial No. 459,997 In Great Britain September r29, 1941 (Cl. (i6-14) 7 Claims.

This invention relates to circular knitting machines, more particularly machines of the kind furnished with sinkers or web holders, and comprises improvements in such machines as will be hereinafter set forth.

The invention is intended for application mainly to circular knitting machines of the characteristic type furnished with double axially opposed, e. g., superimposed, needle cylinders, double-ended needles, latch or bearded, and needle operating sliders, for the purpose f enabling needles to knit in either or both of the needle cylinders in order to produce plain fa rie, rib fabric, or purl fabric automatically accor ing to'requirements, as is now well known in the art, but it may nevertheless be applied to machines of the single cylinder type. In a circular knitting machine equipped with sinkers or web holders the latter are usually moved outwards preparatory to stitch formation and after stitch formation are moved inwards to hold the newly formed loops while the needles are advanced, e. g., raised, to clear preparatory to further stitch formation.

There are times in the operation of a circular knitting machine of the kind described when it may be desired temporarily to suspend knitting on one or more of the needles but at such times the associated sinker or web holder, or sinkers or web holders as the case may be, is or are usually still operated as aforesaid with the result that there ensues undesirable engagement of a sinker or web holder associated with an inactive needle with the yarn which lies across the needles. It is found in practice that this adversely affects the yarn and is conducive to breakage and faulty knitting.

The object of one of the present improvements is to obviate this disadvantage, and in this respect this improvement is advantageously applicable to machines which operate with rotary reciprocatory motion as well as with rotary motion for knitting on a portion of the needles only, as, for example, in making heel and toe pouches in seamless hosiery and in which the undesirable engagement of sinkers or web holders with the yarn occurs on opposite sides of the group of needles active during reciprocating knitting, since when the instep needles are renderedhidle and some of the heel and toe needles are also rendered idleprogressively during narrowing the majority of the corresponding sinkers or Web holders are still operated. Thus when these sinkers or web holders are moved inwards as aforesaid, some at least of them foul the length of yarn which extends between the feeder and the last needle to knit on each stroke of reciprocation.

It has heretofore been proposed to provide, in a machine of the kind described, means for preventing undesirable yarn engagement by sinkers or web holders in circumstances such as those aforesaid, but the present improvement has in view the provision of simpler means for achieving the same result.

According to this improvement provision is made for moving a sinker or web holder associated with an inactive needle inwards irrimediately after the normal outward u rnovement, or substantially so, suchwise tliat'the yarn lying on the outside of the needles extends over the outer (top) edge of the nib or nose of the sinker or web holder and is thereby prevented from undesired engagement by the sinker or web holder.

The distinguishing feature of the present improvement is that the sinker or web holder itself is positioned at the appropriate time and loca- .tionto avoid undesirable engagement with the yarn.

According to another improvement, however, a circular knitting machine of the kind concerned is furnished with outside sinkers and an inside cam system.

In order that the invention may be more clearly understood and readily carried into practical effect, specic examples thereof applicable to a circular seamless hosiery knitting machine of the characteristic type hereinbefore mentioned will now be described with reference to the accompanying drawings in connection with the formation of heel and toe pouches during reciprocating knitting-and in comparison lwith a conventional sinker arrangement having the aforesaid disadvantages.

In the accompanying drawings,

Figure 1 is a detail diagrammatic plan view of the said conventional arrangement illustrating-a few of the needles and sinkers with yarn being fed to the needles during normal knitting,

Figure 2 is a detail elevational view of needles and sinkers of the same arrangement to show conditions obtaining during reciprocating knitting,

Figures 3 and 4 are detail elevation views showing portions of needles and sinkers and the relationship of yarn thereto at different stages during knitting,

Figures 5 and 6 are two views corresponding to Figures 1 and 2 respectively showing, however, one example of the manner in which sinkers may be operated in accordance with the present invention,

Figures 7, 8 and 9 are detail elevational views showing portions of needles, sinkers and yarn as they would appear at respectively different points on Figure 5, as will be hereinafter described,

Figure 10 shows a portion of the'sinker cam system employed for imparting to the sinkers the outward and inward movements indicated in Figure 5,

Figure 11 is a cross-sectional view taken on the line XI-XI of Figure l0,

Figure 12 is a vertical sectional view of so much of a machine of the particular type concerned as is necessary to illustrate the application thereto of the improved sinker arrangement comprising outside sinkerswand anwinside cam System ,if

Figures 13 and 14 are two similar views showing, together with Figure 12, successive stages in the operation of the outside sinkers, and

Figure 15 depicts the relevant portion of the inside camsystem for operating the said outside sinkersl Like parts are designated by similar reference characters throughout the drawings.

Referring to Figure 1, a few of the needles of the machine are shown at 2. Inside sinkers (or web holders) which are arranged to alternate with the needles in the customary manner are indicated at 3. It will be assumed that the needles are provided in a cylinder and the sinkers in an associated bed both of which rotate, during normal knitting, in the direction of the arrow A. At the point marked B, the yarny is being fed to the needles 2 which latter are thereupon immediately retracted to draw loops and thereby form stitches of the yarn, after which the said needles are advanced at point C to clear, preparatory to further stitch formation. Prior to retraction of the needles 2 to draw loops, the sinkers 3 are moved outwards at D but, after stitch formation, they are again moved inwards at E to hold the newly formed loops Z while the needles are advanced as aforesaid. The deviation or wave of the sinkers as they are moved outwards and inwards is indicated by the dot-and-dash line F. In Figure 3 the operative portion of one of the sinkers 3 is shown in its outward position in relation to the yarn y which is being fed into the adjacent needle 2. The numeral 3a represents the nib or nose and 3b the throat of the sinker.

Now, in order to make heel and toe pouches in seamless hosiery, all of the instep needles are rendered inactive or idle and some of the heel and toe needles are also rendered idle progressively during narrowing. That is to say, during the production of such pouches by reciprocating knitting, there is always a group of idle needles and a group of active needles. The idle needles are raised to heeling height. In Figure 2, the few needles bracketed at G are inactive or idle ones, while those bracketed at H are needles at one side of a group of active needles. It is to be understood, of course, that there are other idle needles also at the opposite side of the group of active needles. As reciprocating knitting proceeds the sinkers corresponding to the idle needles still\oper'i,te-` Consequently, when such sinkers are moved inwards at the point E, or at the point D, depending on whether the needle cylinder is turning forwardly in the direction of the arrow A or in the opposite direction for reverse knitting, some at least of them will foul the length y1 of yarn which extends freely at the outside of the idle needles between the feeder 4 and the last active needle such as 21 to knit on each stroke of reciprocation. As the result of its inward movement, a sinker associated with an inactive or idle needle may, for instance, split or/and cut the yarn on its nib or nose 3a as depicted in Figure 4. In the conditions obtaining in Figure 2, there is a tendency for the yarn to be cut by sinkers at the point y2. Or a sinker associated with an inactive needle may tend to take the yarn and drag it inwards between idle needles. As will be appreciated, the foregoing description with reference to Figures 1-4 is common practice, but is given to present to the reader a clearer conception of the difficulties to be overcome by the present invention.

In the preferred manner of obviating the difculties referred to, the gomntlalipkver cam system is modified Tri/such a way that after'desired sinkers 3 have been moved outwards at I (Figure 5) preparatory to stitchwformation, they are immediately patill'wi'tldrawn`-either to J during forward knitting or to K during reverse knitting. In Figure 5 forward (normal) knitting is, of course, taking place in the direction of the arrow A. During such knitting, the yarn y is fed to the needles 2 at the point B in the manner illustrated in Figure 7, whereupon the needles are retracted to draw loops. Simultaneously with this retraction of the needles the sinkers are partially withdrawn to J' so that, at the point L, yarn, in being drawn into a loop by a needle 2, is pulled over the nib or nose 3a of the adjacent sinker 3 in the manner depicted in Figure 8. Then, after stitch formation, the sinker completes its inward movement at M with the result that the yarn enters the throat 3b thereof (see Figure 9). The deviation or wave of the sinkers as they are moved outwards and inwards in two stages is clearly indicated by the dot-and-dash line N in Figure 5. The reader may readily appreciate precisely in what respects this wave differs from normal practice by comparing it with the wave indicated at F in Figure 1. The modified wave is obtained by providing an inside sinker cam system forming a continuous track 5 (Figure 10) which, at the or each knitting location of the machine is shaped as shown to impart the described two-stage outward and inward movements to the sinkers. As shown in Figures 10 and 11, this track is provided between spaced upper and lower cam rings 6 and 1 mounted in a sinker cup 8 of conventional form. At the or each knitting location a portion 6a of the upper ring 6 is made vertically adjustable. In this example, the inside sinkers 3 are provided in a tricked sinker bed 9 which, in accordance with known practice, is mounted on the top of the plain cylinder I0 of the machine. The sinkers are formed with butts such as 3c for engagement in the cam track 5.

Having thus described the modied movements of the sinkers, and the cam means by which such movements are imparted, it is now convenient to consider the manner in which the improved sinker arrangement of this example functions during reciprocating knitting to obviate the particular difliculties aforesaid. This will be done with the aid of Figure 6 which purports to show conditions obtaining during a forward stroke of reciprocating knitting. As will be seen, G are inactive or idle needles at heeling height, while those at H are active needles as hereinbefore described with reference to Figure 2. Thus, when, during a forward stroke, the sinkers corresponding to idle needles are moved partially inwards at the point J (Figure the length y1 of yarn extending on the outside of the idle needles between the feeder 4 and the last active needle 21 to knit will lie over the top edges of the nibs or noses 3a of the said sinkers. In this way the yarn is effectually prevented from undesired engagement by the sinkers. A partially withdrawn sinker with the length of yarn concerned extending harmlessly over the nib or nose thereof is indicated at 3l in Figure 6. Similar conditions will exist on a reverse stroke -only this time partial withdrawal of the rele- Ivant sinkers will, of course, be effected at K instead of at J.

The further example of the invention shown in Figures 12-15 will now be described. Incidentally, Figures 12, 13 and 14 show more clearly the type of machine to which the improvements concerned are principally intended to be applied. Thus, the machine comprises a rotary plain cylinder Il'I, a superimposed rotary rib cylinder I I, doublelended needles such, for instance, as the latch needle I2 (Figure l2), and needle operating sliders such as I3 in both needle cylinders for the purpose of enabling needles to knit in either or both of the latter. In this example, outside holding down sinkers I4 (or web holders) are pivotally mounted in an annular tricked or slotted `bed I5 on the top of the plain cylinder I0, and

are engaged with an inside cam track I6 (see Figure 15) formed between an appropriately lshaped annular part I'I formed integrally with the sinker cup I8 and a cam ring I9 fitted within said cup. Each of the sinkers I4 is formed with a vertical shank or stem I4a and with a horizontal extension I4b. A rounded fulcrum portion I4c is formed between the shank or stem and the said horizontal portion. Each sinker is arranged to turn on its fulcrum I4c about a pivot pin or stud 20. When the sinker is in position in the bed I5 the rounded fulcrum portion I4c thereof is located between the corresponding pivot pin or stud 20, at the underside of the said bed, and the upper end of the plain needle cyl- `inder I0, with the horizontal extension I4b in engagement with the cam track I6. A gate or equivalent (not shown) is provided through which the sinkers can be inserted into and removed from the track. The nib or nose I4d of each sinker I4 extends horizontally from the upper end of the shank or stem I4a and works in a trick or slot I5a formed in the top of the sinker bed I5. At the knitting location the cam track IE is formed so as to Vimpart the customary outward and inward movements tothe sinkers, but instead of being closed at this location by being shaped in the manner indicated by the dot-anddash line O, as in existing arrangements, the cam track is open at 2| and 22 at one side to permit of additional inward movement of sinkers which are associated with some if not all of the needles to be rendered idle during reciprocating knitting. For imparting this additional movement to these sinkers the associated sliders I3 in the plain cylinder I0 are formed as presser elements, for which purpose each is provided with a lateral butt 23 near its upper end for contact with the shank or stem I4a of the associated sinker I4. As usual, the sliders are encircled by a spring band 24 which serves to hold them inwards in their tricks Illa. Normally the lateral butts 23 on the bottom sliders are below the level of the sinkers, which latter therefore operate in the usual manner. When a change is automatically made from circular knitting to reciprocating knitting the instep needles through their sliders I3 are raised to so-called heeling height indicated at P in Figure 12 and during the knitting of a heel or toe pouch the number of the heel and toe needles is gradually reduced (for narrowing) by raising such needles through their sliders to the heeling height, all as now well understood by those familiar with the knitting art. As shown in Figure 12, this brings the lateral butts 23 on the said sliders up behind the Shanks or stems I4a of the associated sinkers I4 so that when these are initially moved outwards as usual the said sliders are also moved outwards against the action of the encircling spring band 24 in the manner illustrated in Figure 13 whereby, when the said sinkers reach the open part 2I or 22 of the cam track I6, depending on whether forward or reverse knitting is taking place, they are immediately pressed inwards by the sliders acting under the inuence of the spring band (see the full line sinker in Figure 14). This brings the nibs I4d of the appropriate sinkers underneath the length of yarn extending from the feeder to the last active needle of the heel and toe group, and this action occurs at each end of the group in turn, i. e., at each stroke of reciprocating knitting. In this application of the invention there will be presser sliders associated with those heel and toe needles which are raised to heeling height P and with all or any required lesser number of the instep needles as may be deemed necessary having regard to the fact that the rotary reciprocation is greater than half of the circumferential extent of the needle circle, in fact it is nearly a complete revolution at each stroke. Consequently all of the sinkers I4 associated with heel and toe needles which are gradually rendered inactive A'forI1adir-OilsingIand 40 some if not most of the sinkers associated with represented in dot-and-dash linesfiriA Figure 14,

and, after having been moved outwards by reason of engagement of its horizontal extension I4b with the cam part IBa of the ring I9, is not moved inwards again until the upper edge of the said extension rides down either the inclined edge I'Ia or the edge I lb of the annular part II-depending on the direction of knitting.

Instead of utilising or relying on a spring band as aforesaid, means such as a cam appropriately formed and arranged may be provided for positive action upon the presser elements, e. g., sliders, for the purpose described.

In a machine furnished with inside sinkers or web holders it may be found more convenient to form appropriate sinkers or web holders with lateral butts, e. g., at the back of the nibs or noses, for engagement by associated sliders when the latter are raised as aforesaid.

The invention may be applied to circular kniti ting machines with stationary cylinders and revolving cam boxes as well as to machines with rotary cylinders and stationary cam boxes and to both single feeder and multi-feeder machines.

What we claim then is:

l. In a circular knitting machine, in combination, a, plain needle cylinder, needles in said cylinder, means for feeding yarn to said needles, desired ones of said needles being movable to an inactive position to enable knitting thereon to be temporarily suspended at required times, a

sinker bed associated with said cylinder, a circular series of inside sinkers slidably mounted in said bed for co-operation with the needles, said sinkers being furnished with operating butts, and sinker cams providing between them a track for the butts, said track being so curved at a knitting location as directly to cause outward movement of the sinkers at one point preparatory to the formation of stitches by the needles, inward movement of said sinkers at another point to enable them to hold down newly formed loops preparatory to further stitch formation, and partial inward movement of the sinkers at a location between said two points and to such an extent that any one of the sinkers associated with an inactive needle is positioned inwardly beyond the yarn feeding to the needles whereby undesired engagement of said yarn by such a sinker is avoided.

2. In a circular knitting machine designed to operate with rotary reciprocatory motion as well as with rotary motion, in combination, a plain needle cylinder, needles in said cylinder, means for feeding yarn to said needles, a group of said needles being movable to an inactive position to enable knitting thereon to be temporarily suspended at such times as reciprocating knitting is taking place on the remaining needles, a sinker bed associated with said cylinder, a circular series of inside sinkers sli'dably mounted in said bed for co-operation with the needles, said sinkers being furnished with operating butts, and sinker cams providing between them a track for the butts, said track being so curved at a knitting location that irrespective as to whether forward or reverse knitting is in progress the sinkers are directly caused to move outwards at one point preparatory to the formation of stitches by active needles, inwards at another point to enable appropriate sinkers to hold -down newly formed loops, and partially inwards at a location between said two points to such an extent that any one of the sinkers associated with an inactive needle is positioned inwardly beyond the yarn feeding to the needles whereby undesired engagement of said yarn by such a sinker is avoided.

3. In a circular knitting machine, in combination, at least one needle cylinder, needles in said cylinder, means for feeding yarn to said needles, desired ones of said needles being movable to an inactive position to enable knittingr thereon to be temporarily suspended at required times, sinkers associated with said needles, a cam system for operating said sinkers, said system forming a continuous track whereby the sinkers are caused to have an outward movement at one point preparatory to the formation of stitches by the needles and an inward movement at another point to enable newly formed loops to be held down by said sinkers while needles are advanced to clear these loops, and a gap being provided in the cam track between the said two points to permit of additional inward movement of any sinker associated with an inactive needle, and means adapted to be rendered operative at the gap as the result of such needle being moved to its idle position for the purpose of imparting the additional inward movement to said sinker to an extent sulcient to position the latter beyond the yarn feeding to the needles whereby undesired engagement of the yarn by the said sinker is avoided.

4. In a circular knitting machine designed to operate with rotary reciprocatory motion as Well as with rotary motion, in combination, a plain needle cylinder, needles in said cylinder, means for feeding yarn to said needles, a group of said needles being movable to an inactive position to enable knitting thereon to be temporarily suspended at such times as reciprocating knitting is taking place on the remaining needles, sinkers associated with said needles, a cam system for operating said sinkers, said system forming a continuous track whereby irrespective as to whether forward or reverse knitting is in progress the sinkers are caused to have an outward movement at one point preparatory to the formation of stitches by active needles and an inward movement at another point to enable newly formed loops to be held down by said sinkers while appropirate needles are advanced to clear these loops, and a gap being provided in the cam system at either side of the point at which sinkers are moved outwards to permit of additional inward movement of any sinker associated with an inactive needle during reciprocating knitting, and means adapted to be rendered operative at the gap as the result of such needle being moved to its idle position for the purpose of imparting the additional inward movement to said sinker to an extent suflicient to position the latter beyond the yarn feeding to the needles whereby undesired engagement of the yarn by said sinker is avoided.

5. In a circular seamless hosiery knitting machine adapted to operate with rotary reciprocatory motion as well as with rotary motion, in combination, a plain needle cylinder, an axially opposed rib cylinder, double-ended needles operable in said cylinders, said needles being divided into an instep group and a heel and toe group, top and bottom sliders in said cylinders for operating the needles, a spring band which encircles the bottom sliders for the purpose of normally holding them inwards in the plain cylinder, means for feeding yarn to said needles, the instep needles being movable to an inactive position at heeling height and some of the heel and toe needles also being similarly movable to said height progressively during narrowing to enable knitting thereon to be temporarily suspended when reciprocating knitting is taking place, those of the sliders in the plain cylinder associated with needles which are to be rendered inactive being provided with a lateral butt, an annular sinker bed on the top of the plain cylinder, a circular series of outside holding down sinkers in said bed, and any inside cam system for operating said sinkers, said system forming a continuous track whereby the sinkers, irrespective as to whether forward or reverse knitting is in progress, are caused to have an outward movement at one point preparatory to the formation of stitches by active needles and an inward movement at another point to enable newly formed loops to be held down by said sinkers while needles are advanced to clear these loops, and a gap being provided in the cam track between the said two points to permit of additional inward movement of any sinker associated with an inactive needle, the construction and arrangement being such that as needles are raised to heeling height the lateral butts on the corresponding bottom sliders are brought up behind the associated sinkers so that when these are initially moved outwards as usual the said sliders are also moved outwards against the action of the encircling spring band whereby, when said sinkers reach the gap in the cam track, they are immediately pressed inwards by the sliders acting under the influence of the spring band, all substantially as and for the purpose herein specified.

6. In a' circular knitting machine, in combination, a plain cylinder, an axially opposed rib cylinder, double-ended needles operable in said cylinders, means for feeding yarn to said needles, desired ones of the needles being movable to an inactive position to enable knitting thereon to be temporarily suspended at required times, outside holding down sinkers associated with needles in the plain cylinder and an inside cam system for operating said sinkers, said system being adapted r-to cause outward movement of the sinkers at one point preparatory to the forma.- tion of stitches by the needles and inward movement of `said sinkers at another point to enable them to hold newly formed loops preparatory to further stitch formation and being, moreover, formed .suchwise as to permit of partial inward movement of the sinkers before the needles completely draw stitches and to an extent sulcient to position the said sinkers inwardly beyond the yarn feeding to the needles whereby undesired engagement of the yarn by sinkers associated with inactive needles is avoided.

'1. In a circular knitting machine, in combination, at least one needle cylinder, needles in said cylinder, means for feeding yarn to said needles, desired ones of said needles being movable to an inactive position to enable knitting thereon to be temporarily suspended at required times, sinkers associated with said needles, a cam system designed to cause (a) normal outward movement of the sinkers at one point preparatory to the formation of stitches by the needles, (b) normal inward movement of said sinkers after stitch formation to enable them to hold newly formed loops preparatory to further stitch formation and (c) partial inward movement of the sinkers before the needles completely draw stitches and to an extent suflicient to position the said sinkers inwardly beyond the yarn feeding to the needles whereby undesired engagement of the yarn by sinkers associated with inactive needles is avoided, the means for moving the sinkers inwards to the extent concerned consisting of an individual presser element associated with the sinker.

THOMAS CHARLES BROMLEY. ARTHUR SHORTLAND. 

